You don't trim any fishes tail. If you do your fish will undoubtedly get fungus and die.
This is not a Betta question so it belongs elsewhere.
There are half moon betta, delta betta, round tail betta, long tailed betta, crown tailed betta, king betta, and others I don't know of yet.
A crowntail is a beta fish with a teardrop-shaped fan tail. The tail of a crowntail beta distinguishes it from other betas. The crowntail is a Siamese fighting fish that grows to 1.5-inches in length.
Stagnant ponds and rice patties in the Vietnam area. They breathe air because the water doesn't have any oxygen in it.
Betta eggs develop in the cluster of floating bubbles the male makes at the surface of the water. Before that, they're in the female...
crown tail bettas.
It means they are getting ready to MATE
In their natural habitat they live in puddles in Asia.But in a fish tank I would put some smooth gravel with one or two fake plants.
fishs eddy
Betta fish grow to be an average of 2 inches from head to the beginning of the tail.
Please describe the growth and where abouts it is on the tail. REAL ANSWER-It is ok if they have it, it is not bad, they are just growing. My betta fish has this.-Mii Bunny UPDATE* Is it fallling off?then it's tail rott.-Mii Bunny
A normal length for a fully grown Betta male is around 2 inches excluding the tail fin.